Friday, December 27, 2019

Nanospectrometer through single nanowire

Overview of nanospectrometer research

nanospectrometer made of single nanowire
Scientists at the University of Cambridge, U.K., designed an ultra-miniaturized device that could image single cells without the need for a microscope or make chemical fingerprint analysis possible with a smartphone camera.
Made of a single nanowire, the new device is the smallest spectrometer ever created. Most modern nanospectrometers are bulky, and are based around principles similar to what Isaac Newton first demonstrated with his prism in the 1600s—the spatial separation of light into different spectral components.

Size of newly developed nanospectrometer

Researchers have now produced a system up to 1000 times smaller than those previously reported. The Cambridge team, working with colleagues from the U.K., China, and Finland, used a nanowire whose material composition is varied along its length, enabling it to respond to different colors of light across the visible spectrum. Using techniques similar to those employed for making computer chips, they then created a series of light-responsive sections on the nanowire. The team hopes the tiny platform will lead to a new generation of ultra-compact nanospectrometers. View more materials research news

Reference :

Friday, December 20, 2019

New insulator inspired by Polor Bear hair

Structure of Polor bear hair

Polor Bare in arctic circle
To survive in Arctic conditions, polar bears must rely on insulation supplied by their own fat, skin, and fur. For engineers, polar bear hair is an ideal template for synthetic mate­rials that could lock in heat just as ef­ficiently. Now, materials scientists at the University of Science and Technol­ogy of China (USTC) have developed such an insulator, reproducing the structure of individual hairs with the goal of building a material composed of many hairs for applications in archi­tecture and aerospace. Unlike the hair of other mammals, polar bear hair is hollow. Examined under a microscope, each one has a long, cylindrical core punched through its center. The shapes and spacing of these cavities are not only responsible for their distinctive white coats, but also the source of re­markable heat-holding capacity, water resistance, and stretchiness.

Construction of new insulator

To imitate this structure and scale it to a useful size, researchers manu­factured millions of hollowed-out car­bontubes, each equivalent to a single strand of hair, and wound them into a spaghetti-like aero­gel block. Compared to other aerogels, the new hollow-tube design is lighter weight and more resistant to heat flow, say researchers. The new material is also ex­traordinarily stretchy, even more than the hairs themselves, further boosting its usefulness. 
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Tuesday, December 17, 2019

global investment in renewable energy 2019

Highlights of global investment in renewable energy

renewable energy through Solar panels
Worldwide investment in renewable energy capacity is on track to have roughly quadrupled in the past decade, according to the Global Trends in Renewable Energy Investment 2019 report, released ahead of the UN Global Climate Action Summit. Global investment in this sector from 2010 throughc2019 is set to hit $2.6 trillion, with more gigawatts of solar power capaciity than any other generation technology. 

Solar power will have drawn half of the $2.6 trillion in renewable energy investments made over the decade. 

The global share of electricity generation accounted for by renewables reached 12.9% in 2018, up from 11.6% in 2017. This avoided an estimated two billion tons of carbon dioxide emissions last year alone—a substantial savings given global power sector emissions of 13.7 billion tons in 2018. 

The cost-competitiveness of renewables has also risen dramatically. The levelized cost of electricity is down 81% for solar photovoltaics since 2009; for onshore wind, it’s down 46%. China has been the biggest investor in renewables capacity over this decade, having committed $758 billion between 2010 and the first half of 2019, with the U.S. second on $356 billion and Japan third on $202 billion. Europe invested $698 billion in renewables capacity over the same period, with Germany and the United Kingdom contributing the most. 

Saturday, December 14, 2019

EDS (Energy dispersive X ray spectroscopy) for nanoparticle research

EDS xray technology

Energy dispersive x ray spectroscopy
Energy dispersive x ray spectroscopy (EDS, or EDX) is an important electron microscopy tool for materials characterization and is commonly used in a wide range of applications and industries from manufacturing to energy and resource management to consumer-packaged goods. Despite the wide use of EDS, the technique has limitations in certain applications, such as difficulty in obtaining high-quality images of polymers, catalysts, and other nanoparticles sensitive to damage from the electron beam. Next-generation Energy dispersive x ray detectors such as Thermo Fisher Scientific’s Dual-X have helped to meet these challenges. Today’s advanced EDS detectors are overcoming the barriers to EDS analysis by making it quick and easy to obtain quality results without requiring expertise and making it possible to obtain high-resolution images of beam-sensitive materials, which were previously unobtainable.

The ability to apply EDS acquisition and automated processing to a broader range of samples will enable taking nanoparticle research to new levels, paving the way toward new applications in industries ranging from food to medicine to textiles and energy research.

Function of EDS Xray

EDS is used to characterize the chemical composition of samples by taking advantage of the fact that every atom has a unique number of electrons that reside in specific positions, or shells, around the nucleus of the atom. Under normal conditions, the electrons in a specific shell have discrete energies. As an electron beam strikes the inner shell of an atom, it knocks an electron from the shell, leaving a hole. When the electron is displaced, it attracts another electron from an outer shell to fill the void. As the electron moves from the outer to the inner shell of the atom, it loses some energy and the energy difference generates an x-ray with an energy and wavelength unique to the specific element.

X-rays emitted during the process are collected by silicon drift detectors, which separate the x-rays of different elements into an energy spectrum. Software is then used to analyze the spectrum and determine specific elements contained within the sample.

Latest developments in Energy dispersive X ray spectroscopy

As the use of EDS expands to include beam-sensitive materials, automation breakthroughs are simplifying the technology, extending its applications. Fully embedded Dual-X EDS detectors enable:

Automated EDS tomography for fast access to 3D chemical information. The microscope can be set up to automatically acquire 3D chemical information overnight unattended.

STEM and EDS Maps software for automated acquisition of statistically relevant data on large area images at high resolution. Data from different imaging and analysis modalities are easily correlated including on-the-fly processing and statistics using Thermo Fisher’s visualization and analysis software Avizo.
An automatic correction for absorption, which adjusts for holder geometry and detector dimensions. The absorption correction is embedded into the company’s Velox software, making it possible to obtain accurate elemental quantification information.

These features make EDS far easier to use, extending the technique to more users, while increasing research productivity. After EDS maps are created, they are stored together with other microscopy information, making it easy to combine and correlate data captured from different microscopy techniques. This enables researchers to completely characterize samples using a single tool.

Potential development of EDS Xray in nanoparticle research

Next-generation EDS detectors are advancing nanoparticle research at institutions around the world. For example, researchers at University of Physics of Materials in Brno, Czech Republic used the detectors to investigate a sample where a large-area, high-resolution EDS map of gold-nickel nanoparticles were acquired in less than one minute. The non-toxic gold nanoparticle combined with the magnetic properties of nickel atoms are promising carriers of surface-anchored agents, which can attach to therapeutic drugs and precisely target them to specific cells in the human body using a controlled release. 

Researchers at Xi’an Jiaotong University, China, is using the detectors to map the effectiveness of nanoparticles such as platinum and cobalt as catalysts in the production of hydrogen fuel. Hydrogen is the most widely proposed fuel for use in fuel cell-powered cars, promising a new generation of vehicles that combine the sustainability of electric cars with the large driving range of conventional fossil fuels. Catalyst nanoparticles are needed to optimize the production of hydrogen fuel via photocatalysis. The catalyst uses the synergistic effects of platinum and cobalt nanoparticles to improve hydrogen productivity.

These are just two examples where next-generation EDS detectors, with their rapid ability to characterize beam-sensitive materials are leading to breakthroughs in nanoparticle\ research. In the future, we can expect to see high-resolution EDS imaging of a wider range of nanoparticles, which, in turn, will deepen our understanding of nanoparticles and their applications across a diverse range of industries. More News

For more information:
Yuri Rikers,
Product Manager Talos at Thermo Fisher
Scientific, Zwaanstraat 31 G/H, 5651
CA Eindhoven, The Netherlands, +31
40.2356000, yuri.rikers@thermofisher.
Reference : Advance materials processing November Edition 2019

Friday, December 13, 2019

Economical fuel cell catalyst from thin graphene based platinum films

Fuel cell catalyst
Researchers at the Georgia Institute of Technology, Atlanta, are using ultrathin, graphene supported platinum films to enable fuel cell catalyst with unprecedented catalytic activity and longevity.

Why platinum films used as fuel cell catalyst?

Platinum is one of the most commonly used catalysts for fuel cells because of how effectively it enables the oxidation reduction reaction at the center of the technology. But its high cost has motivated research efforts to find ways to use smaller amounts of it while maintaining the same catalytic activity.

Most platinum-based catalytic systems use the metal’s nanoparticles chemically bonded to a support surface, where surface atoms of the particles do most of the catalytic work, and the catalytic potential of the atoms beneath the surface is never utilized as fully as the surface atoms—if at all.

To prepare their atomically thin films, the Georgia Tech researchers used a process called electrochemical atomic layer deposition to grow platinum monolayers on a layer of graphene, creating samples that had one, two, or three atomic layers. They found that the bond between neighboring platinum atoms in the film essentially combines forces with the bond between the film and the graphene layer to provide reinforcement across the system. That was especially true in the platinum films that were two atoms thick.

New platinum films are potentially long-lasting

Additionally, the new platinum films at that minimum thickness outperformed nanoparticle platinum in the dissociation energy, which is a measure of the energy cost of dislodging a surface platinum atom. The measurement suggests such films could make potentially longer-lasting catalytic
Reference :
Advanced material processing November 2019 Edition

Wednesday, December 11, 2019

Naturally extracted graphene from Eucalyptus bark

naturally extracted graphene
A new method for producing graphene was recently developed by scientists at RMIT University, Australia, and the National Institute of Technol­ogy, Warangal, India. The technique uses Eucalyptus bark extract and is less expensive and more sustainable than existing synthesis techniques, accord­ing to researchers. 

Cost of graphene production

RMIT lead scientist Suresh Bhargava says the new tech­nique could lower the cost of production from $100 per gram to just 50 cents per gram. Professor Vishnu Shanker from the National Institute of Technology, Warangal, says the “green” chemistry avoids the use of poisonous reagents, possibly paving the way for the use of graphene in biocompatible materials. When tested in a supercapacitor, the graphene created by the new technique matched the performance and quali­ty of traditional graphene.

Reference :
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